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Merged
deepthi merged 3 commits into from
Feb 17, 2021
Merged

Report lag stats in poller #7490

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bf11ac0
Report lag stats in poller
5antelope Feb 13, 2021
d1b2dc8
use simple gauge and rm tags
5antelope Feb 16, 2021
dc0d5cf
rename
5antelope Feb 16, 2021
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17 changes: 16 additions & 1 deletion go/vt/vttablet/tabletserver/repltracker/poller.go
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Original file line number Diff line number Diff line change
Expand Up @@ -20,21 +20,35 @@ import (
"sync"
"time"

querypb "vitess.io/vitess/go/vt/proto/query"

"vitess.io/vitess/go/stats"

"vitess.io/vitess/go/vt/mysqlctl"
vtrpcpb "vitess.io/vitess/go/vt/proto/vtrpc"
"vitess.io/vitess/go/vt/vterrors"
)

var replicationLagGauges = stats.NewGaugesWithMultiLabels(

@deepthi deepthi Feb 16, 2021

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None of the vttablet metrics have the keyspace/shard dimensions because by definition a tablet belongs to only one keyspace/shard. This can be a simple gauge (NewGauge).
Also the name should include the units - replicationLagMs or replicationLagNs.
HeartbeatLag is being reported in nanoseconds so we should probably do the same here.

@5antelope 5antelope Feb 16, 2021

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Sure, I renamed the gauge to replicationLagSec since we always assume the lag in seconds (e.g., we have SecondsBehindMaster and also cast the duration to sec on line 60)

@deepthi deepthi Feb 16, 2021

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That makes more sense than ns :)

"replicationLag",
"replication lag",
[]string{"Keyspace", "Shard"})

type poller struct {
mysqld mysqlctl.MysqlDaemon

mu sync.Mutex
lag time.Duration
timeRecorded time.Time

keyspace string
shard string
}

func (p *poller) InitDBConfig(mysqld mysqlctl.MysqlDaemon) {
func (p *poller) InitDBConfig(mysqld mysqlctl.MysqlDaemon, target querypb.Target) {
p.mysqld = mysqld
p.keyspace = target.Keyspace
p.shard = target.Shard
}

func (p *poller) Status() (time.Duration, error) {
Expand All @@ -55,5 +69,6 @@ func (p *poller) Status() (time.Duration, error) {

p.lag = time.Duration(status.SecondsBehindMaster) * time.Second
p.timeRecorded = time.Now()
replicationLagGauges.Set([]string{p.keyspace, p.shard}, p.lag.Milliseconds())
return p.lag, nil
}
6 changes: 5 additions & 1 deletion go/vt/vttablet/tabletserver/repltracker/poller_test.go
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Expand Up @@ -21,15 +21,19 @@ import (
"testing"
"time"

querypb "vitess.io/vitess/go/vt/proto/query"
topodatapb "vitess.io/vitess/go/vt/proto/topodata"

"github.com/stretchr/testify/assert"

"vitess.io/vitess/go/vt/mysqlctl/fakemysqldaemon"
)

func TestPoller(t *testing.T) {
target := querypb.Target{Keyspace: "k", Shard: "s", TabletType: topodatapb.TabletType_REPLICA}
poller := &poller{}
mysqld := fakemysqldaemon.NewFakeMysqlDaemon(nil)
poller.InitDBConfig(mysqld)
poller.InitDBConfig(mysqld, target)

mysqld.ReplicationStatusError = errors.New("err")
_, err := poller.Status()
Expand Down
2 changes: 1 addition & 1 deletion go/vt/vttablet/tabletserver/repltracker/repltracker.go
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Expand Up @@ -76,7 +76,7 @@ func NewReplTracker(env tabletenv.Env, alias topodatapb.TabletAlias) *ReplTracke
func (rt *ReplTracker) InitDBConfig(target querypb.Target, mysqld mysqlctl.MysqlDaemon) {
rt.hw.InitDBConfig(target)
rt.hr.InitDBConfig(target)
rt.poller.InitDBConfig(mysqld)
rt.poller.InitDBConfig(mysqld, target)
}

// MakeMaster must be called if the tablet type becomes MASTER.
Expand Down